Concept design of the proton linac for the JAEA-ADS

JAEA-ADS用陽子リニアックの概念設計

田村 潤  ; 長谷川 和男; 近藤 恭弘   ; 前川 藤夫  ; 明午 伸一郎   ; Yee-Rendon, B. 

Tamura, Jun; Hasegawa, Kazuo; Kondo, Yasuhiro; Maekawa, Fujio; Meigo, Shinichiro; Yee-Rendon, B.

The Japan Atomic Energy Agency (JAEA) is proposing an accelerator-driven subcritical system (ADS) as a future project to transmute long-lived nuclides to short-lived or stable ones. In the JAEA-ADS, a high-power proton beam of 30 MW with the beam energy of 1.5 GeV and with the beam current of 20 mA at an exit of the accelerator is required with sufficient reliability. Furthermore, the linac needs to be operated in a continuous wave (CW) mode in order to be compatible with the reactor operation. Since a normal conducting (NC) structure raises a difficulty in cavity cooling under the CW operation, a superconducting (SC) linac would be a suitable solution. In the proposed linac, the high-intensity proton beam is accelerated by an NC radio-frequency quadruple (RFQ) and low-beta SC cavities such as a half-wave resonator (HWR) and a single-spoke resonator (SSR), and finally accelerated to the designed beam energy of 1.5 GeV by elliptical cavities. To ensure the required reliability for the JAEA-ADS, doubling the ion source and the low-beta region of the linac is also proposed. Because the requirement of reliability is far beyond the capability of the current technology and the operating experience in the Japan Proton Accelerator Research Complex (J-PARC) linac, a stepwise approach of developing each accelerator component is required. In this workshop, a concept design of the proton linac for the JAEA-ADS is discussed.